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8: Taxonomy, Systematics & Phylogeny

  • Page ID
    218618
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    • 8.1: Taxonomy & Classification
      This page explains that all life on Earth shares a common ancestor, represented through phylogenetic trees, which detail evolutionary relationships within the domains of Archaea, Bacteria, and Eukarya. It covers the hierarchy of taxonomy and systematics, including binomial nomenclature. It clarifies that branch lengths in phylogenetic trees do not reflect evolutionary time but sequence.
    • 8.2: Determining Evolutionary Relationships
      This page discusses the use of morphologic and genetic evidence to understand evolutionary relationships among organisms through concepts like homologous and analogous structures. Molecular systematics and phylogenetics are vital for analyzing these connections, aiding in disease understanding and conservation. Cladistics organizes organisms by shared traits, relying on assumptions about common ancestry and speciation.
    • 8.3: Features Used to Classify Animals
      This page explores animal classification through body plans and embryonic development, emphasizing body symmetry and germ layer counts. It discusses the significance of coeloms in triploblastic organisms, differentiating acoelomates, pseudocoelomates, and eucoelomates, and highlights how their mouth formation influences developmental processes.
    • 8.4: Animal Phylogeny
      This page explores the evolution of animal phylogeny, transitioning from fossil records to molecular analyses, which reveal relationships among animal phyla. It classifies Metazoa into Eumetazoa and discusses key clades like Bilateria, Ecdysozoa, and Lophotrochozoa. The page emphasizes the reclassification of organisms and emerging phyla, reflecting the evolving nature of phylogenetic trees influenced by genetic data.


    This page titled 8: Taxonomy, Systematics & Phylogeny was last modified on Fri, 28 Aug 2026 23:54:33 GMT and is shared under a not declared license and was authored, remixed, and/or curated by OpenStax.

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